1. Field of the Invention
The present invention relates to the recovery of catalyst components and, more particularly, to a process for the recovery of zero-valent nickel complexes from the stream obtained by the hydrocyanation of olefins, e.g., from the preparation of adiponitrile by hydrocyanation of butadiene using nickel complexes as catalysts with triarylboranes, e.g., triphenylborane as the catalyst promoters.
2. Description of the Prior Art
The hydrocyanation process to which the present invention is particularly applicable is described in U.S. Pat. No. 3,496,218 issued on Feb. 17, 1970. Catalyst used in the process is zero-valent nickel; a particular form of which is described in U.S. Pat. No. 3,766,237 issued on Oct. 16, 1973.
U.S. Pat. No. 4,082,811 issued on Apr. 4, 1978 discloses a hydrocyanation process coupled with a method for recovery of the catalyst. The particular operation to which the present invention is applied is found in column 2, lines 39-42 of this patent.
The feasibility of extracting nickel catalyst mixture from dinitriles and specifically from adiponitrile is discussed in detail in U.S. Pat. No. 3,773,809 issued on Nov. 20, 1973. This patent discloses several organics which may be employed in the extraction process along with detailed analyses of the phases which are obtained upon extraction. In column 4, lines 3-15 the use of an arylborane compound as a catalyst promoter is disclosed.